With the exception of sensory neurons, the role of a neuron's is to carry information toward the cell body, whereas the role of the is to carry information away from the cell body.

Dendrites; axon

Neuron is a cell that carries electric impulse and considered as the basic unit of nervous system. Every neuron has parts which are the dendrites, cell body and axon. Dendrites and axons are nerve fibers and neurons are supported by glial cells and astrocytes. Neurons are connected to one another. They are do not touch but forms gap called synapses. Chemical and electrical synapses passes signals via chemical or electrical impulses.

It is evolution, because we all have some of the same traits like eye color or shape or ears.